Increasingly, consumers are relying on packet switched networks for the delivery of content. An ubiquitous example of such reliance is the delivery of a myriad of different types of content via the Internet. In order to facilitate the delivery of content via the Internet, it is common for consumers to have high-speed, or broadband, Internet connections. These connections often take the form of a cable or digital subscriber line modem/router that acts as a bridge between a wide area network (“WAN”), such as the Internet, and a consumer's own local area network (“LAN”). While these broadband connections provide much greater bandwidth than older connections available over a traditional public switched telephone network, even with such a broadband connection obtaining the high QOS network access required for high bandwidth content can be problematic.
Content in the form of video is one type of high bandwidth content that is very sensitive to the network limitations inherent in most broadband Internet connections used today. This video content can take the form of both video content transmitted over the Internet, and Internet Protocol Television (“IPTV”), which transmits video content over private networks distinct from the Internet. In both cases, a delay in transmitting packets can result in signal degradation in the form of pixelization or, at worst, a blank video screen, both of which being unacceptable to consumers. Such signal degradation can be remedied by increasing the bandwidth available to the consumer.
One problem currently faced in increasing bandwidth is providing a suitable “last mile” network infrastructure. The “last mile” refers to the final leg of delivering connectivity from a communications provider to a consumer, and includes the wiring that provides connectivity within residences such as houses or apartment buildings, for example. Wiring that relies on electrical signals to convey content through the last mile, such as standard category 5, 5e, and 6 cables (“Ethernet cables”) used in traditional Ethernet applications, can be susceptible to noise or interference that results in signal degradation. Such noise or interference is generally non-periodic, cross-coupled “spiky” or “transient” interference (hereinafter collectively referred to as “transients”) caused by using certain twisted pairs within the Ethernet cables for traditional telephony signals (such as category 3 cable), which signals are inductively coupled to and consequently cause transients in the twisted pairs used for Ethernet signals. Transients are also caused by running the category 5/5e/6 cable in close proximity to alternating current (“AC”) power lines within the house or apartment building, which lines are also inductively coupled to and consequently cause transients in the Ethernet cables. In either case, the result of such transients is that the common-mode rejection benefits associated with Ethernet cables that result from their shielding and use of differential signalling are overwhelmed by the transients, and the transmission of Ethernet signals is noticeably impeded.
To overcome the effects of these transients, telecommunication companies are experimenting with networks that rely, in part, on optical signals for communication. Optical signals, which are immune to transient interference, can be transmitted over optical fibers such as plastic optical fiber (“POF”). Two or more optical fiber cores can be joined together in parallel, and sheathed within an outer covering of sheathing material which physically interconnects but optically separates the parallel optical fiber cores, wherein one fiber core can be used as a transmission path and one fiber core can be used as a reception path, thereby allowing for full-duplex communication. A pair of optical fiber cores so joined together is hereinafter referred to as “duplex optical cable”; a pair of plastic optical fiber cores so joined together is hereinafter referred to as “duplex POF cable”. FIGS. 3(a) and 3(b) (PRIOR ART) are simplified line drawings of a common type of duplex POF cable, such as Mitsubishi International Corporation's ESKA™ 2.2 mm duplex POF cable. This cable 30 consists of dual, separate inner cores 32 of plastic optical media for transmitting optical signals, the cores 32 bonded to and held within a plastic outer covering of sheathing material 31 which optically separates but physically interconnects the two inner cores 32.
Networks that rely on optical signals often utilize a centralized media converter distribution node and remote end-point media converters to establish a network that is effectively immune to interference caused by transients. The network typically uses duplex POF cable 30, which is usually hidden from view within the walls of a building, to transmit an optical signal from the centralized distribution node to the end-point media converters, which are wall-mounted. At the centralized distribution node and end-point media converters, which are typically located well away from interfering transients, optical signals can be converted to electrical signals, which can subsequently be transmitted using category 5/5e/6 cable. Category 5/5e/6 cable extending from the end-point media converter can then be coupled to a consumer device such as a computer, for example, thereby providing network connectivity to the consumer device.
As such optical networks become more pervasive, a need is emerging for a simple termination mechanism that will allow the POF cable 30 not only to reside within the walls of a building, but to be able to connect directly to, and to terminate within, consumer devices that require a network connection. Direct termination of POF cable 30 within a consumer device is desirable as it avoids the use of thick and cumbersome category 5/5e/6 cable, and as it avoids the conversion of optical signals into electrical signals, thereby simplifying and reducing the cost of the network infrastructure.
FIGS. 1(a), 1(b), 2(a), and 2(b) (all PRIOR ART) illustrate duplex POF cable connectors that are known in the art. FIGS. 1(a) and 1(b) depict a Firecomms EDL300T-220 OptoLock Ethernet Fiber Optic connector 10. This connector 10 contains both high-speed photodiode and LED devices (not shown) to facilitate both reception and transmission of optical signals, respectively. Connected to a main connector body 11 is a large fluted front 12, containing two separate entry apertures 13 for insertion of prepared POF cable 30. By “prepared POF cable”, it is meant POF cable 30 that has been partially split lengthwise at one end, such as by using a very sharp utility or X-acto™ knife, such that a gap 33 exists between the two strands of POF that make up a typical piece of POF cable 30. The connector 10 has no integrated cutting mechanism for splitting the POF cable 30, and therefore only prepared POF cable 30 can be used.
After inserting the cable 30, the fluted front 12 is pressed towards the main connector body 11 as indicated in FIG. 1(b) by the arrow. Pressing the fluted front 12 into the main connector body 11 secures the POF cable 30 within the connector 10. Prior to pressing the fluted front 12 into the main connector body 11, the cable 30 is able to freely slide into and out of the main connector body 11. While this connector 10 is effective and useful for industrial and laboratory use, the rather large size of the connector body 11 (16 mm wide×12 mm high×14 mm deep) and large (12 mm deep) fluted front 12 preclude it from being used in many types of consumer devices such as laptops, switches and routers. Additionally, the fluted front 12 requires too much force to be pushed into the connector body 11 to be effectively integrated into a portable consumer device or a device with a high density arrangement of connectors.
Referring now to FIGS. 2(a) and 2(b), there is shown a simplified line drawing of an Avago Technologies SPFEIM100_G Consumer Fast Ethernet connector 20. As with the Firecomms connector 10, this connector 20 contains both high-speed photodiode and LED devices (not shown) to facilitate both reception and transmission of optical signals, respectively. A main connector body 21 contains two separate entry apertures 23 that allow for insertion of prepared POF cable 30. After cable insertion, a front lever 22 is pressed downwards across the main body 21 toward POF cable 30, which secures the POF cable 30 within the connector 20, as indicated in FIG. 2(b) by the arrow. Prior to depressing the front lever 22, the cable 30 is able to freely slide into and out of the main body 21. While this connector 20 is effective and useful for automotive use and for use in a highly vibratory environment, its size (20 mm wide×18 mm high×17 mm deep, with a 5 mm deep lever) and protruding lever mechanism 22 preclude it from being used in many forms of consumer devices such as laptops, switches or routers. Pushing the front lever 22 downwards requires too much force to allow the connector 20 to be effectively integrated into a portable consumer device, and the connector 20 is physically too large to be used in a consumer device that requires a high density arrangement of connectors.
Consequently, there exists a need for a optical fiber cable connector that is small enough to be used on a consumer device that requires a high density arrangement of connectors, and that can be used with unprepared optical fiber cable having multiple cores.